Gene said:ABB-A=DD or
DD+A=ABB
Since you are adding a single digit to a two digit number there can only be one to carry so A = 1.
Now you have
DD+1=1BB
The only digit you can add 1 to and get a carry is 9 so D=9
That's the way you do it. If you need more help, show me how far you have gotten on the others.
\(\displaystyle 1)\;\;\begin{array}{ccc} A\;B\;B \\ - \quad A \\ \hline \;\;\;D\; D \end{array}\)
\(\displaystyle 2)\;\;\begin{array}{c}\quad E\;E \\ +\;F\;F \\ \hline E\;E\;K\end{array}\)
\(\displaystyle 3)\;\;\begin{array}{c}\;\;\;P\;A \\ +\;A\;P \\ \hline P\;U\;G \end{array} \quad\Leftarrow \quad\text{This problem has }no\text{ solution!}\)